1. Ocean Water Chemistry
Section 13.3

2. Salinity The amount of dissolved salt in water
The ocean has 35g of salt per 1kg water or
35g salt per 1000g water
3.5% salinity
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3. What kind of salt is in ocean?
Most of the salt is sodium chloride which breaks up in to sodium ions and chlorine ions
Other kinds of salt are in the ocean
(sulfate, magnesium, calcium, potassium and others)

4. Variations of salinity
Increased salinity
- at surface (evaporation)
- at poles (water freezes)
Decreased salinity
- at mouths of rivers (fresh water added)
(Brackish water)
- at surface (precipitation)

5. Effects of salinity Lower freezing temperature (-1.9oC) Higher density
Greater bouyancy

6. Ocean Properties Temperature drops as you move away from equator
Water is colder and denser the deeper you go
CO2 is more plentiful than in air
O2 is more scarce (especially in deeper and warmer water)

7. Temperature Zones Surface – warmest (top 100-500m) Transition zone –
Temps drop quickly
to 4oC (from surface
to1km deep)
Deep – average temperature
is 3.5oC

8. Pressure in ocean Pressure increases with depth
Divers can only descend 40m
Submersibles can go deeper